Vietnamese K-50M submachine gun is a conversion of a Chinese-made Type 50 submachine gun (a license-built version of the Soviet Shpagin PPSh-41). During the sixties, China supplied many small arms to North Vietnam, including Type 50 submachine guns, many of which were later converted into more compact and maneuverable K-50M versions by local Vietnamese workshops. Conversion included shortening of the barrel jacket, installation of the new front sight, removal of the wooden stock and installation of the pistol grip and telescoped buttstock made of steel wire. All internal components remained the same as in Type 50 / PPSh-41.

K-50M submachine gun is a blowback-operated weapon that fires from open bolt, in single shots and full automatic. Fire mode selector is located in front of the trigger, safety is built into the bolt handle. Receiver of the weapon is stamped from steel. Gun uses PPSh-41-type 35-round curved box magazines, use of 71-round PPSh-41 drums is possible only if the telescoping butt is retracted. Open sights feature flip-up L-shaped rear blade, set up for 100 and 200 meters range.